First popularized in England, the image was taken with a twin-lens camera and exposed on a glass-plate negative.Printed on paper and mounted on heavy stock, the image appears 3-dimensional when viewed through a stereoscope or stereopticon.
The tintype is a photographic process that extended from the mid- to late -1850s into the first third of the 20th century. Tintypes use thin black or brown lacquered iron sheets on which to record the images.Whereas cased daguerrerotypes and ambrotypes proved bulky to ship, inexpensive uncased tintypes and tintypes mounted on cartes-de-visites (pictorial calling cards) could be exchanged more easily between camp and home, making it the photo process of choice.
The first of the cased image processes, the daguerreotype arrived from Europe in late 1839. Reflective like mirrors, daguerreotypes produce reversed images. The process records images onto a layer of silver. The surface is highly vulnerable to tarnishing and abrasion. With its use of toxic mercury vapors, the daguerreotype process was a dangerous as well as expensive and time-consuming undertaking.
An ambrotype cased image differs from a daguerreotype in that the photographer recorded the image on to less-expensive glass rather than a copper plate by using the same basic wet-plate collodion process made famous by Matthew Brady and other field photographers. The ambrotype employs a thin or underexposed glass-plate negative that creates a positive image when superimposed on a black background.